Ultrasonic wave cleaning apparatus

ABSTRACT

An apparatus for physically cleaning objects by using ultrasonic waves which employs a unique arrangement of a cleaning liquid tub and a plurality of ultrasonic wave oscillators. The arrangement is such that the cleaning tub comprises two oppositely inclined bottom walls in generally V-shaped cross-section, and the ultrasonic wave oscillators are installed on one of the inclined bottom walls of the cleaning liquid tub having a relatively smaller area than the conventional flat bottom construction. By virtue of this arrangement, the ultrasonic waves can be radiated much more effectively leaving less dead space than in the conventional construction, thus resulting in such advantageous features as remarkable improvement of the radiation effects of ultrasonic waves on the object to be cleaned and effective reduction of the number of ultrasonic wave oscillators without sacrificing the ultrasonic wave cleaning effect.

United States Patent [191 Tatebe [11] 3,873,071 [451 Mar. 25, 1975ULTRASONIC WAVE CLEANING APPARATUS Noriyasu Tatebe, Tokyo, JapanKabushiki Kaisha Tatebe Seishudo, Tokyo-to, Japan Aug. 1, 1973 [75]Inventor:

[73] Assignee:

U.S. Cl. 259/72, 134/184 Int. Cl BOIf 11/02 Field of Search 259/72, DIG.41, DIG. 42;

26l/DIG. 48; 134/1, 111, 184

[56] References Cited Primary ExaminerHarvey C. Hornsby AssistantExaminer-Alan Cantor [57] ABSTRACT An apparatus for physically cleaningobjects by using ultrasonic waves which employs a unique arrangement ofa cleaning liquid tub and a plurality of ultrasonic wave oscillators.The arrangement is such that the cleaning tub comprises two oppositelyinclined bottom walls in generally V-shaped cross-section, and theultrasonic wave oscillators are installed on one of the inclined bottomwalls of the cleaning liquid tub having a relatively smaller area thanthe conventional flat bottom construction. By virtue of this arrangementthe ultrasonic waves can be radiated much more effec tively leaving lessdead space than in the conventional construction, thus resulting in suchadvantageous features as remarkable improvement of the radiation effectsof ultrasonic waves on the object to be cleaned and effective reductionof the number of ultrasonic wave oscillators without sacrificing theultrasonic 1W l nin e s 8 Claims, 2 Drawing Figures I I IPATENTEDMARZSISYS FIG.

FIG. 2

1. ULTRASONIC WAVE CLEANING APPARATUS BACKGROUND OF THE INVENTION Thepresent invention relates generally to an art in the field of physicalcleaning and particularly to an ultrasonic'wave cleaning apparatus. Moreparticularly, this invention is concerned with an ultrasonic wavecleaning apparatus of laterally inclined radiation type which isadaptable for a medical bacteria-free cleaning treatment to objects suchas doctors hands and medical instruments to be cleaned prior to asurgical operation.

It has been well known to use ultrasonic waves for removing oils andother contaminants off from instruments. For such a purpose,conventional ultrasonic wave cleaning apparatus have employed anultrasonic wave radiation system in which a plurality of ultrasonic waveoscillators are arranged horizontally along a flat horizontal bottom ofa cleaning liquid chamber of the apparatus. With such an arrangement ofthe ultrasonic wave oscillators, unless such wave oscillators areprovided in quantity in proportion to the area of the bottom of thecleaning liquid chamber, substantial effect of ultrasonic cleaningcannot be obtained as desired, and therefore, it has been necessary withsuch conventional arrangement to dispose a plurality of ultrasonic waveoscillators with appropriate spaces between each other extensivelythroughout the whole bottom area of the chamber.

When it is desired to have an incresed effect of ultrasonic cleaning inthe design of such apparatus, it has been'a practice to increase thenumber of ultrasonic wave oscillators to be provided alongthe bottomarea of the chamber. In this respect, the cost of such oscillators perone cleaning apparatus inevitably became considerably large, which costsometimes amounted to almost a third of the total price of theapparatus, thus resulting in a costly apparatus, and this fact was anobstacle to extensive use of such apparatus.

In addition, when such an apparatus of the conventional arrangement isused for a hand-cleaning or a therapeutical treatment, an effectiveultrasonic wave cleaning performance is obtained with respect to skinsurfaces such as of the fingers, etc., as the cleaning liquid is causedto positively pass into the surfaces of such objects in an extremelyshort period.

However, it has been experienced that there is no substantial effectobtained specially .in the nailback portions of the fingers which aremost likely to be contaminated by bacteria and so much so that thenailback portions should essentially be cleaned bacteria-free in thisparticular application. This is because the radiation of ultrasonicwaves tends to be diffused at random due to the horizontal arrangementof the ultrasonic wave oscillators on the bottom of liquid chamber, andconsequently, no substantial ultrasonic wave cleaning effect is obtainedin the nailback portions of the fingers which require a stronglyconcentrated radiation of ultrasonic waves for striking and removing thecontaminants lodged therein.

SUMMARY OF THE INVENTION According to this invention, there is providedan ultrasonic wave cleaning apparatus including a plurality ofultrasonic wave oscillating means on the wall of a cleaning liquid tubadapted for radiating ultrasonic waves into the body of cleaning liquidcontained in the tub, the cleaning apparatus incorporating theimprovement comprising a bottom wall inclinedly extending upwardlytoward one side of the cleaning liquid tub and a plurality of ultrasonicwave oscillating means arranged on the other side of the tub,theultrasonic wave oscillating means being mounted to radiate beams ofultrasonic waves in an obliquely upward direction generally parallelwith the inclined bottom wall.

A preferred embodiment of the invention will now be described by way ofexample and with reference to the accompanying drawing in which likeparts are designated by like reference numerals.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a side elevational view, partly in vertical section, showingthe interior arrangement of an ultrasonic wave cleaning apparatus ofinclined radiation type according to this invention, and

FIG. 2 is a top plan view of the apparatus shown in FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to theaccompanying drawing, there is shown a cleaning tub 2 which defines acleaning liquid chamber W. The cleaning tub 2 has a bottom of V- shapedcross section which comprises a laterally inclined bottom wall 20 andanother oppositely inclined bottom wall 2b; as seen in FIG. 1 wall 2bhas a greater inclination with respect to the horizontal as compared tothat of wall 2a. Wall 2a thus has a greater length than wall 2b. Theinclined bottom wall 2a extends obliquely upwardly from the bottomcorner towards one lateral side of a casing 3. In an opening provided inthe inclined bottom wall 2b, there are provided a plurality ofultrasonic wave oscillators 4 each of which has a high frequency coil 4bwound around an iron core 4a so as to produce ultrasonic waves asspecified. This arrangement is specifically designed for keeping to aminimum a dead space or area where there is no substantial effect ofultrasonic waves radiated from the ultrasonic wave oscillators 4 withrespect to a cleaning liquid contained in the cleaning liquid chamber W.

These ultrasonic wave oscillators 4 are, for instance, bonded inposition on a base plate 6 by using a suitable adhesive, and themarginal portion of the base plate 6 is secured fluidtightly on thesides 7 of the opening in the inclined bottom wall Zbof the cleaning tub2 by a plurality of screws 8 with a suitable packing (not shown)therebetween. An auxiliary liquid chamber 9 is provided for receivingtherein the cleaning liquid overflowing from the liquid chamber W whenan object to be treated is immersed into the liquid in the liquidchamber W, the auxiliary chamber 9 being separated by a partition orweir 10 from the cleaning liquid chamber W.

At the bottom of the auxiliary chamber 9, there is provided a cleaningliquid drain hole 11 having therein a filter 11a, the drain holecommunicating with a threeway valve 13 through a pipe 12. One deliveryport of the-three-way valve 13 is connected to the suction side On theother hand, a drain pipe 19 opening at the bottom of the cleaning tub 2is communicatively connected with the abovementioned pipe 17. Thedelivery side of the pump is connected through a pipe 21 to cleaningliquid discharging outlets 22 which are formed in the base plate 6 ofthe ultrasonic wave oscillations 4. There is further provided a highfrequency generator at the bottom of the casing 3. In the abovedescribed arrangement of the ultrasonic wave cleaning apparatus, thecleaning tub 2 is filled with the cleaning liquid.

In operation, an object to be treated or cleaned is immersed in thecleaning liquid in the chamber W and a radio frequency current from theultrasonic wave generator 20 is applied to the oscillating coils 4b ofthe ultrasonic wave oscillators 4, whereby ultrasonic waves are radiatedfrom the oscillators 4 disposed on the obliquely inclined bottom wall 2bof the cleaning tub 2 in a variety of directions with respect to theinclined bottom wall 2a of the cleaning tub 2 as indicated by phantomarrows in FIG. 1, such as more or less obliquely upwardly, in parallel,or more or less obliquely downwardly with respect to the inclinedbottomwall 2a of the cleaning tub 2.

Among these ultrasonic waves, portions or beams of ultrasonic wavesradiated in relatively downward radiating directions so as to collide atcertain varied angles with the bottom wall 2a will be reflected so as tobe redirected into the body of the cleaning liquid in the cleaning tub 2according to the angles of incidence to the wall 2a. Consequently, thereoccura variety of irregular reflections of ultrasonic waves on theinclined bottom wall 2a, and this results in relatively uniformlydistributed radiations of the ultrasonic waves throughout the cleaningtub 2.

Asa consequence of the above described radiating operation, there isobtained a generally upward radiating effect of ultrasonic waves withrespect to the cleaning liquid in the cleaning tub 2, so that thecleaning liquid is as a whole exposed to such radiation of ultrasonicwavesfrom the bottom portion towards the upper portion thereof, andthere remains only a small portion of the liquid existing at the upperright side of the cleaning tub 2 as viewed in FIG. 1 that is not wellsubjected to the radiation of ultrasonic waves, whereby the objectimmersed in the cleaning liquid is subjected to generally uniformradiating effects of ultrasonic waves throughout almost all of theportions thereof. The best cleaning effect is obtained particularly onthe part of the object which faces the inclined bottom wall 2a.

When the three-way valve 13 is changed over so as to connect the pipe 12with the pipe 14, and a motor Mis operated tr drive the pump 15, thecleaning liquid issucked by the pump 15 from within the auxiliary liquidchamber 9 through the pipe 12 and then delivered via the pipe 21 and thedischarging outlets 22 back into the liquid chamber W. An extra quantityof the'cleaning liquid in the cleaning liquid chamber W overflows intothe auxiliary liquid chamber 9, and the liquid is thus repeatedlyrecycled to the liquid chamber W.

Since jet streams of the cleaning liquid are ejected out of thedischarging outlets 22 located at the bottom portion of the tub 2, thereis produced a recirculation flow or convection of the cleaning liquidwithin the cleaning tub 2. The jet streams of the cleaning liquid causedislodging of the contaminants on the surfaces of the object beingtreated in the cleaning tub 2. When the surfaces of the object thus madefree from contaminants are further exposed to the abovementioned effectsof ultrasonic waves, a remarkably improved cleaning effect can beobtained.

The contaminants removed from the surfaces of the object are thendirected into the auxiliary liquid chamber 9, being entrained by thecleaning liquid, and are finally trapped by the filter 11a in the drainhole 11. Consequently, the cleaning liquid to be recycled to the tub 2is made free from contaminants.

In the practice of the cleaning apparatus of this invention, a preferredfrequency range of ultrasonic waves was found to be between 20 and 38KHz, and a preferred output range of ultrasonic waves between 0.1 and0.2 Watt/em From the results of breeding experiments on thestaphylobacillus and staphylococcus in the nailback portions of thehuman fingers by using the ultrasonic cleaning apparatus of theconventional horizontal bottom arrangement, it was found that the numberof colonies (quantitative unit of bacteria) increased from 98 coloniesup to 186 colonies, which was a considerably adverse effect due to theuse of such ultrasonic wave cleaning apparatus. In contrast, when theultrasonic wave cleaning apparatus of laterally inclined oscillatorarrangement according to this invention was used, experiments underidentical conditions in terms of the same staphylobacillus andstaphylococcus in the nailback portions'of the fingers produced aremarkable result in that the number of colonies decreased from 205 to 0with a single cleaning operation.

In summary, the ultrasonic wave cleaning apparatus according to thisinvention has the following advantageous features. First, the timerequired for the cleaning operation can be made remarkably shorter thanby the conventional arrangement, so much so that the service life of theapparatus can be substantially prolonged. Second, equal cleaning effectcan be attained by applying only about one-third output of ultrasonicwaves in comparison with the conventional arrangement, thus resulting inconsiderable savings in economy. In addition, a substantial reduction inthe number of ultrasonic wave oscillators is accordingly possible whilemaintaining equal cleaning performance, thus considerably contributingto a further wider application of the ultrasonic wave cleaningapparatus.

While this invention has been described above with respect to only anapplication thereof to a handcleaning operation for doctors prior to asurgical operation, this does not mean in any way a limitation of thisinvention, but on the contrary, this invention can likewise be appliedto many other uses such as, for instance, for cleaning medical devicesand instruments by commonly using special medical fluids.

ate ultrasonic waves into a cleaning liquid contained in 5 said tub:

wardly over a greater length than said first bottom wall, saidultrasonic wave oscillating means being oriented to radiate theultrasonic waves obliquely upwardly along and parallel to said secondbottom wall, said tub being fully open upwardly at the upper edge of thebottom walls.

2. An ultrasonic wave cleaning apparatus as claimed in claim 1, furthercomprising means for injecting said cleaning liquid into said cleaningliquid tub.

3. An ultrasonic wave cleaning apparatus as claimed in claim 2, furthercomprising means for sucking said cleaning liquid from within saidcleaning liquid tub and recirculating said liquid to said injectingmeans.

4. An ultrasonic wave cleaning apparatus as claimed in claim 3 whereinsaid sucking means includes liquid pumping means.

5. An ultrasonic wave cleaning apparatus as claimed in claim 3, furthercomprising change-over means disposed in said sucking and recirculatingmeans to selectively direct said cleaning liquid to said cleaning liquidtub through said pump and said injecting means, or to a drain.

6. An ultrasonic wave cleaning apparatus as claimed in claim 2 whereinsaid injecting means includes means for directing the cleaning liquid ina direction generally parallel with said inclined bottom wall.

7. An ultrasonic wave cleaning apparatus as claimed in claim 1 furthercomprising an auxiliary liquid tub adjoining said cleaning liquid tub,and weir means between said tubs for overflowing of said cleaning liquidfrom said cleaning liquid tub into said auxiliary tub.

8. An ultrasonic wave cleaning apparatus as claimed in claim I, furthercomprising filter means adapted to filter said cleaning liquid flowingout of said cleaning liquid tub.

1. In an ultrasonic wave cleaning apparatus including an opentopcleaning liquid tub having a bottom of V-shaped cross section, includinga pair of first and second oppositely inclined bottom walls, andultrasonic wave oscillating means on said first bottom wall to radiateultrasonic waves into a cleaning liquid contained in said tub: animprovement wherein said second bottom wall is less inclined withrespect to the horizontal than said first bottom wall so as to extendobliquely upwardly over a greater length than said first bottom wall,said ultrasonic wave oscillating means being oriented to radiate theultrasonic waves obliquely upwardly along and parallel to said secondbottom wall, said tub being fully open upwardly at the upper edge of thebottom walls.
 2. An ultrasonic wave cleaning apparatus as claimed inclaim 1, further comprising means for injecting said cleaning liquidinto said cleaning liquid tub.
 3. An ultrasonic wave cleaning apparatusas claimed in claim 2, further comprising means for sucking saidcleaning liquid from within said cleaning liquid tub and recirculatingsaid liquid to said injecting means.
 4. An ultrasonic wave cleaningapparatus as claimed in claim 3 wherein said sucking means includesliquid pumping means.
 5. An ultrasonic wave cleaning apparatus asclaimed in claim 3, further comprising change-over means disposed insaid sucking and recirculaTing means to selectively direct said cleaningliquid to said cleaning liquid tub through said pump and said injectingmeans, or to a drain.
 6. An ultrasonic wave cleaning apparatus asclaimed in claim 2 wherein said injecting means includes means fordirecting the cleaning liquid in a direction generally parallel withsaid inclined bottom wall.
 7. An ultrasonic wave cleaning apparatus asclaimed in claim 1 further comprising an auxiliary liquid tub adjoiningsaid cleaning liquid tub, and weir means between said tubs foroverflowing of said cleaning liquid from said cleaning liquid tub intosaid auxiliary tub.
 8. An ultrasonic wave cleaning apparatus as claimedin claim 1, further comprising filter means adapted to filter saidcleaning liquid flowing out of said cleaning liquid tub.